It's Not An Angel.

천사가 아니야, Not an Angel, She's No Angel, She's Not an Angel, It's Not an Angel, Cheonsa-ga Aniya
Authors: Yuna Park, Pyoryu
Genres: Psychological, School, Romance, Drama

Read It's Not An Angel. full chapter on MangaScans. Father Daniel is a new teacher at Kaebiji Private High School, a school that is known for being a dump where all the local delinquents gather. He is adjusting to his new life well until one night when he stumbles upon a woman while on patrol... and finds her beating a man. Sensing that something is off, Father Daniel reports the incident to the faculty the next day, only to realize that the woman, Miss Sasha, is also a teacher at the school. A strange relationship between a devoted priest and a kind teacher both disguised as angels begins... (Source: Webtoon Entertainment). Wish you have a pleasant reading experience at MangaScans